Garbage air compressor.. Need Help!

[Zodiac_col]

It was my first time buying a used compressor since the last one I had was brand new.
The used compressor was 1 year old and the day I went to get it, the compressor wasn't working. It kept tripping the breaker so I thought it might be a problem with their house electrical system. They told me to come back later. Then, they got it working and it seem good. I checked that the compressor was holding pressure and drain the tank from bottom to see that it was not rusted and only a few clear drops came out. So I paid and brought it home. I got home and realized that it was overfilled with oil since the level of oil was above red dot so high i could see the actual level. Anyway, I did oil change and filled to red dot. When the pump had no oil throught the oil change I put it on its side and remove the drain fitting at the bottom to clean it. I found so much rust that it was blocking the small hole so it was only allowing small drop to come out. I clean that part and put it back up and a lot of rusty water come out :'( . Well, that not being the worst issue I decided to run it (after oil had settled for more than 12 hr) so it works good then I turn it off and release the pressure. I turn it back on and i saw that one of my fuses blows up from the old electrical box full of fuses like small light bulbs instead on breakers. I change the fuse try it again and it blowed again. Even thought the compressor worked on this outlet I decided to try a different one that seem to be better (coming right from the electrical box with no cable-share). I plugged it in turn it on and it worked like it should. I turn it off release the pressure (took me about 5 mins) then turn it back on and another fuse blowed up. I dont wanna keep blowing fuses.

I really need help, dont know what to do. What do you think is causing it?
The compressor is a CHINESE **** with a 120 volts 15 amps motor that says 6.5 HP for which I know its not true and 30 gal tank

 

[Monkey Milk]

I had a cheap craftsman compressor, the "oil free" one and it use to always trip the beaker until I tore the cover off and found the connecting rod was binding on the motor or some thing around that area. I don't know if your compressor is the "oil free" type but that is the problem I had with mine.

 

[G_P]

A 15a motor on a 15a circuit will blow fuses as its inital startup current is much higher. You might try slo-blow fuses and see if that cures the problem.

If this is a belt drive compressor remove the belt and see if the motor still blows fuses. Also spin the pump by hand and feel for any binding.

Sent via carrier pigeon.

 

[RCStocker]

Nothing wrong with fuses. They work but what size wire is to the out let and how far. You might be drawing more amps than the line will deliver.
Try a 20 am fuse to see if it blows. Do not leave it in. You might need to run a dedicated line just for the compressor. I have a 20 gallon portable with a full 2 hp motor and a v head. It blows circuit breakers all the time. It is one hell of a compressor. It is a mini commercial. I used it on the job sites and ran it off the power pole. When it is on check the line draw for voltage and see what you have. It could be a compressor problem but more times than not it is an electrical drop that blows.

 

[Zodiac_col]

A 15a motor on a 15a circuit will blow fuses as its inital startup current is much higher. You might try slo-blow fuses and see if that cures the problem.

If this is a belt drive compressor remove the belt and see if the motor still blows fuses. Also spin the pump by hand and feel for any binding.

Sent via carrier pigeon.

how would I increase the amp outage for this circuit lets say 20 amps so that this does not happen again...is it possible to do and my compressor can take 20 amps even if its rated 15 amps...?

 

[Haukur]

Your motor could be connected to a 200 amp circuit as long as the voltage matches. The motor only draws the amps it needs, you can't force-feed it amps. But it can get too many volts, then the magic smoke will escape.

 

[Zodiac_col]

Your motor could be connected to a 200 amp circuit as long as the voltage matches. The motor only draws the amps it needs, you can't force-feed it amps. But it can get too many volts, then the magic smoke will escape.

Voltage wise I believe its good. For the amperage if the motor is drawing more than 15 amps at the beginning should I increase the amperage of the fuses at the breaker box?

 

[kenfain]

Voltage wise I believe its good. For the amperage if the motor is drawing more than 15 amps at the beginning should I increase the amperage of the fuses at the breaker box?

What size wire is run from the fuse panel, to the compressor, or outlet? While you might try a 20 amp fuse, you'll need to be sure the wire can take that many amps. As you already know your drawing over 15. A slow blow 15 amp fuse could work. But I believe, that if the wire is of a large enough guage, that a 20 amp is the way to go. Probably needs to be at least 12 guage wire, just to be safe. Is there enough space in the panel, for another circuit? Is the panel close to the compressor? If yes then the fix is easy. If the problem isn't in the compressor.

 

[Zodiac_col]

I removed the electric motor and as I spin the pulley I hear a grinding noise...I have remove the pulley, the two covers at each end and the question is...
Can I put grease on the rotor of the motor? I believe this will help with the noise since bearings are o.k.

 

[Farmall450]

I had a cheap craftsman compressor, the "oil free" one and it use to always trip the beaker until I tore the cover off and found the connecting rod was binding on the motor or some thing around that area. I don't know if your compressor is the "oil free" type but that is the problem I had with mine.

His isn't, or he wouldn't have changed the oil

 

[Zodiac_col]

What size wire is run from the fuse panel, to the compressor, or outlet? While you might try a 20 amp fuse, you'll need to be sure the wire can take that many amps. As you already know your drawing over 15. A slow blow 15 amp fuse could work. But I believe, that if the wire is of a large enough guage, that a 20 amp is the way to go. Probably needs to be at least 12 guage wire, just to be safe. Is there enough space in the panel, for another circuit? Is the panel close to the compressor? If yes then the fix is easy. If the problem isn't in the compressor.

If the wire happen to be hidden is there a way to know what gauge is it?
I try putting a 20 amp fuse and it blow up as well. Should I try the slow blow?

 

[Haukur]

I would either try to find another "user" that draws the same amps and try your circuit or take the motor to a friends or neighbors garage and see if their fuse/breaker handles it.

That is the easy way to narrow it down. You could also measure and test the motor, but the other way requires no special tools, other than a trailer, pick-up or a dolly to wheel it across the street to a neighbors house.

 

[kenfain]

If the wire happen to be hidden is there a way to know what gauge is it?
I try putting a 20 amp fuse and it blow up as well. Should I try the slow blow?

If your blowin a twenty, I'd have to think there's a problem with the compressor. You can check the wire size at the outlet, or the service panel. Just take the cover off the panel. At the outlet you can check wires, by taking off the cover, if you can't see clearly, pull out the receptacle. A slow blow twenty isn't a good idea, unless you know for sure you've got at least #12 wire. Either way you're gonna want to know the size wire you've got on any circuit that's drawing the limit, for the fuse that was originally installed. This thing is reaching the limit, if you push it past it's possible to burn it up, your house with it. Now that being said, it's possible, even likely, it's got # 12. That's industry standard I believe. But it'd be better if you could just add a circuit, provided the service panel is close by. Then you have options, and you know for sure.

 

[Zodiac_col]

If your blowin a twenty, I'd have to think there's a problem with the compressor. You can check the wire size at the outlet, or the service panel. Just take the cover off the panel. At the outlet you can check wires, by taking off the cover, if you can't see clearly, pull out the receptacle. A slow blow twenty isn't a good idea, unless you know for sure you've got at least #12 wire. Either way you're gonna want to know the size wire you've got on any circuit that's drawing the limit, for the fuse that was originally installed. This thing is reaching the limit, if you push it past it's possible to burn it up, your house with it. Now that being said, it's possible, even likely, it's got # 12. That's industry standard I believe. But it'd be better if you could just add a circuit, provided the service panel is close by. Then you have options, and you know for sure.

Well I can arrenge and move compressor close to service panel...what would be the ideal circuit to be added in this case? wire gauge and fuse?

 

[taumac]

That compressor may surge at start up more than 15amp but running at 15amp..... Check the pressure switch on the compressor. You might have a short in switch.

 

[Zodiac_col]

That compressor may surge at start up more than 15amp but running at 15amp..... Check the pressure switch on the compressor. You might have a short in switch.

How would I check that? just opened the cover and all cables seem ok...not stripped or anything like that...Is there a way to check this with a multimeter?

 

[kenfain]

Well I can arrenge and move compressor close to service panel...what would be the ideal circuit to be added in this case? wire gauge and fuse?

Me? I'd put in way bigger wire than I need, maybe #10 in your case. Probly use a twenty amp fuse. Doesn't have to be close to the panel. Just makes things cheaper and easier. My gut feeling is, you've got a compressor problem. Since it was tripping breakers before. It doesn't sound like you've got any way of checking amp draw. I'd think about takin off the belt, see if the motor burns a fuse by itself. No? Then turn the pump by hand. Listen and feel, it should be smooth turning. Might make funny noises, like gurgling or air popping sounds. That's normal, grinding, scraping, and such are not. Still no problem? That's probly good news, means it'll likely be simple to fix, cheaper maybe. Harder to diagnose though. And you'll likely need pictures to get specific help. Also make & model a must. The good news is, that there's a few pro compressor people here. Someone will know exactly what to check &how

 

[Zodiac_col]

Me? I'd put in way bigger wire than I need, maybe #10 in your case. Probly use a twenty amp fuse. Doesn't have to be close to the panel. Just makes things cheaper and easier. My gut feeling is, you've got a compressor problem. Since it was tripping breakers before. It doesn't sound like you've got any way of checking amp draw. I'd think about takin off the belt, see if the motor burns a fuse by itself. No? Then turn the pump by hand. Listen and feel, it should be smooth turning. Might make funny noises, like gurgling or air popping sounds. That's normal, grinding, scraping, and such are not. Still no problem? That's probly good news, means it'll likely be simple to fix, cheaper maybe. Harder to diagnose though. And you'll likely need pictures to get specific help. Also make & model a must. The good news is, that there's a few pro compressor people here. Someone will know exactly what to check &how

Thanks a lot!!!! I got a start point now... I have lubricated the motor and I will install it back to the compressor...also will check the electric connection and make sure of the proper gauge wire and fuse. The pump does not seem to be grinding as I turn it.

 

[G_P]

If the motor scrapes and grinds when turned by hand I doubt lubing it will fix it. The bearings are shot.

Now you know why it was put up for sale. The seller knew it was junk.

Sent via carrier pigeon.

 

[Givl Reggin]

You should be using "Type-S" fuses - these are slow blow and allow for momentary over load (like when a motor starts) without blowing. Also make note of what else is on that circuit and may be running at the same time.

Until you actually measure the amperage draw, whatever the motor is doing is just guess work at best.

Get yourself one of these (clamp-on amp meter):

and make one of these:

Then measure the start up current and running current - a 15 amp motor should not be pulling 15 amps unless it's near a stall condition - 12-13amps is where it should be under load.

Since it's a used compressor you really don't know the history and at some point someone may have changed the pulley size to increase pump output - if so the motor may not be able to handle the increase in rotational force and is pulling more amps than it should.

If the pump is making a 'grinding noise' that's not a good sign either - bad bearings are certainly one source, pistons/rods could also be a problem - this could also be contributing to the motor overload condition.

 

[taumac]

I would put thing back together. You can use clamp meter like one mentioned above. OK, When a motor start such as a compressor it surges at start up its a normal thing. This is why you dont run a refrigerator on a GFI breaker cause the surge at start up will pop the GFI. BEFORE i go tearing out walls and doing electrical work take it to friends or someone esles house and try running it on a stand alone outlet or one thats not running much say 15 amp breaker and see if pops the breaker. If it doesnt then its the circuit you are trying to run it on at your house. If it does then im believe its a short in pressure switch or could be it cap. First test it at somewhere esle. What happens? Pops or doesnt? If pops its compressor not circuit. Then take motor and run it off compressor not through pressure switch. By its self nothing else. What happens? Runs or pops fuse? If pops fuse motor shot or could be bad cap. If nothing put back on and try it thru pressure swicth. Retest and what happens?

 

[Ben Buck]

Are you using an extension cord on this compressor? If so, this could be adding to the fuse blowing situation.

 

[Zodiac_col]

Well...Thanks for all suggestions!!!!

I lube the motor clean a little breather valve on top of the pump(exhale from there)...and believe it or not I think this was causing the problem it was plug with dirt.

NOT A CIRCUIT PROBLEM: As I mention before it was shooting brakers at the previous house owner. At my place, the outlet for the compressor is a 12- Gauge wire which is directly coming from the box with nothing connected to it.
I put a new 20 amps in this circuit and is working now!!!
I disconnected the pulley and put the motor by itself and out of 10 trials I did (on/off) never flip breaker. Then I connected the pump and started to work.
The question is should I leave this set-up alone for this circuit???
(AWG -12 wire and 20 amp fuse) -Only compressor is alone in this circuit-

 

[Zodiac_col]

You should be using "Type-S" fuses - these are slow blow and allow for momentary over load (like when a motor starts) without blowing. Also make note of what else is on that circuit and may be running at the same time.

Until you actually measure the amperage draw, whatever the motor is doing is just guess work at best.

Get yourself one of these (clamp-on amp meter):

and make one of these:

Then measure the start up current and running current - a 15 amp motor should not be pulling 15 amps unless it's near a stall condition - 12-13amps is where it should be under load.

Since it's a used compressor you really don't know the history and at some point someone may have changed the pulley size to increase pump output - if so the motor may not be able to handle the increase in rotational force and is pulling more amps than it should.

If the pump is making a 'grinding noise' that's not a good sign either - bad bearings are certainly one source, pistons/rods could also be a problem - this could also be contributing to the motor overload condition.

Very informative!!!
1- How do I set-up this device to measure the start up current and running current.
2 - I really do not thick pulley was removed by owner since the paint covering all bolts everywhere was intact. Even the oil drain plug was never removed. It looked like I was the first to removed the pulley. But let us remember that this a CHINA made compressor and I wouldn't be surprised if the used the wrong diameter of pulley.
3- The motor was not making any grinding noise neither the pump. One of the small valves where compressor exhale the air was plugged really bad. I believed that was causing poor pump performance (Not sure though). Motor bearing are good.
4- I have set it up on a circuit just for compressor with AWG-12 wire and 20 amp fuse... Should I change the 20 amps to a 15 amps Type -S? (Let us remember that the original was a 15 amp and when it blew I was suggested to change it for a 20 amps which is working right now)

 

[taumac]

good deal..... glad it worked out.

 

[kenfain]

Very informative!!!
1- How do I set-up this device to measure the start up current and running current.
2 - I really do not thick pulley was removed by owner since the paint covering all bolts everywhere was intact. Even the oil drain plug was never removed. It looked like I was the first to removed the pulley. But let us remember that this a CHINA made compressor and I wouldn't be surprised if the used the wrong diameter of pulley.
3- The motor was not making any grinding noise neither the pump. One of the small valves where compressor exhale the air was plugged really bad. I believed that was causing poor pump performance (Not sure though). Motor bearing are good.
4- I have set it up on a circuit just for compressor with AWG-12 wire and 20 amp fuse... Should I change the 20 amps to a 15 amps Type -S? (Let us remember that the original was a 15 amp and when it blew I was suggested to change it for a 20 amps which is working right now)

I wouldn't necessarily add the slow fuse at fifteen amps. Even though that's what they're made for. I would stay with the twenty. As long as it's running properly, the fifteen will be okay. But the twenty, to me would be the way to go. It gives a small margin, and is within safety guidelines. If the fifteen blows, it could be from the motor overworking, possibly because of something stopped up? On the other hand, if the twenty goes, you've likely got a problem. That's the first step in fixing something, is knowing there's a problem. As long as the fuse goes before the wire, you'll be okay. And a twenty amp, will definitely go before the #12 wire. Now if your unit pulled twelve amps, it would be different. But fifteen amp fuse is too close to the actual load. Some might say it's safer for the motor, but I'd say that you'd likely end up occasionally changing fuses. Your call though. I hope I've explained it right, feel free to ask any questions.

 

[Zodiac_col]

I wouldn't necessarily add the slow fuse at fifteen amps. Even though that's what they're made for. I would stay with the twenty. As long as it's running properly, the fifteen will be okay. But the twenty, to me would be the way to go. It gives a small margin, and is within safety guidelines. If the fifteen blows, it could be from the motor overworking, possibly because of something stopped up? On the other hand, if the twenty goes, you've likely got a problem. That's the first step in fixing something, is knowing there's a problem. As long as the fuse goes before the wire, you'll be okay. And a twenty amp, will definitely go before the #12 wire. Now if your unit pulled twelve amps, it would be different. But fifteen amp fuse is too close to the actual load. Some might say it's safer for the motor, but I'd say that you'd likely end up occasionally changing fuses. Your call though. I hope I've explained it right, feel free to ask any questions.

Yes, you have explained it right!!!! Thanks a lot...

I wanted to make sure if it was safe to run 20 amps Max on # 12 wire....

I will then leave it like that ....Not concerned about the compressor that much since as I said before the compressor was overfilled with oil so much I couldn't see the level line through the glass sight and never changed the oil. Previous owner was running it like that and I know as a fact that will screw the pump. I know the compressor is not in the best shape possible so I dont have to worry about little more amps...
Now tomorrow I can use my compressor to do a big steering and suspension job...Hopefully it will handle the use an abuse well since I really have to use it for some components...